International Journal of Hydrogen Energy, Vol.45, No.7, 4829-4840, 2020
Creep fracture behavior of the Crofer 22 APU for the interconnect of solid oxide fuel cell under different temperatures
Creep damage and creep crack growth (CCG) behavior of Crofer 22 APU as interconnect of solid oxide fuel cell at different temperatures are investigated by the continuum damage mechanics method through CT specimen. It is illustrated that the fracture time of CT specimen reduces with temperature increasing at the same stress level, they are 1297 h, 42 h, 1.8 h and 0.25 h, respectively, at 650, 700, 750 and 800 degrees C with stress level of 2.73 MPa.root m. The slopes of creep fracture mechanics parameter C* to CCG rate <(a)over dot> (C*- rate of a) are nearly the same at 650 and 700 degrees C. The slope of C*- <(a)over dot> at 650 and 700 degrees C is smaller than that at 750 and 800 degrees C. It is concluded that the temperature effect on CCG behavior of Crofer 22 APU is more evident than that the stress effect. All the data of C*- <(a)over dot> fall within the area of 95% prediction band, and the obtained equation of C* and CCG rate is <(a)over dot> = 3.8e2C(*0.91). Therefore, the <(a)over dot> of Crofer 22 APU can be predicted under different stress levels and temperatures. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.